MAC Address Withdrawal Over Static PW

draft-boutros-pwe3-mpls-tp-mac-wd-01.txt

Sami Boutros Siva Sivabalan

Luca Martini

Background• MAC withdraw mechanism over static PW:

– Based on PW OAM message defined in “draft-ietf-pwe3-static-pw-status-01.txt”

– A given MAC withdraw notification is not refreshed for ever

– Acknowledgment of OAM messages is mandatory

– Duplicate messages are identified using sequence number in order to avoid repeated (unnecessary) flushing of MAC address(es)

MAC Withdraw OAM Message 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 0 0 0 1 |Version| Reserved | 0xZZ PW OAM Message | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ACH TLV Header | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Refresh Timer | TLV Length |A| Flags | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1|0 | Sequence Number TLV | TLV Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | MAC List TLV | ~ PE-ID TLV (optional) ~ | MAC Flush Parameter TLV (optional) | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

MAC Withdraw OAM Message (cont’d)

• Refresh Timer field is not used

• Message without Sequence Number TLV is dropped

• ACK message (A bit set) does not include MAC TLVs

Operation• A sender re-transmits a MAC withdraw message

with a given sequence number if it does not receive ACK for that sequence number

• A receiver always acknowledges any incoming MAC withdraw message (new or duplicate)

• A receiver processes a MAC withdraw message only if the sequence number of that message is greater than that of the last processed MAC withdraw message

Thank You !